What is cellulitis?

Cellulitis is a common skin infection caused by bacteria (germs). The infection makes the skin look swollen and red and feel hot and sore.

Cellulitis can occur on any part of the body. It can start with a small area that then gets bigger.

Signs and symptoms of cellulitis

Your child may have cellulitis if an affected area of skin is:

  • swollen
  • painful
  • red
  • hot and tender

Causes of cellulitis​

Cellulitis occurs when bacteria (germs) enter your child’s body through a scratch, cut, or other break in the skin. The bacteria are mostly Group A streptococcus and staphylococcus. You might not be able to see where the bacteria enter.

Your child is more likely to get this infection if they have:

  • dry or flaky skin
  • other skin conditions such as eczema
  • burns, scratches, splinters, cuts or scrapes
  • spider or insect bites
  • recent surgery

Legs and feet are common areas for the bacteria to enter the body. Your child may have trouble using his arms or legs if they are infected.

What your doctor can do for cellulitis

Your child’s doctor will complete a physical examination to find out if your child has cellulitis. Your child may also need a blood test. The doctor or nurse may outline the affected area with pen to see if the infection is spreading.


If your child has a very mild infection, your child’s doctor may suggest an antibiotic cream. If the infection is mild to moderate, your child’s doctor will prescribe an antibiotic to treat the infection. Your child can usually take this antibiotic orally (by mouth).

Your child might need an intravenous antibiotic (one delivered through the vein) if their infection is more severe.

After your child starts antibiotics, the area of redness can sometimes become worse before it gets better. The infection should begin to improve after a few days of treatment.

Taking care of your child at home

Finish all antibiotics

Even if your child is feeling better, continue to give them the antibiotics until they are finished. The infection can come back, especially if treatment is not completed properly.

Treat fever and pain

Give your child acetaminophen or ibuprofen to treat fever or pain. You can also help decrease pain by applying cool packs to the affected area.

Complications of cellulitis

Cellulitis can cause serious complications if it is not treated. These include abscesses, infection in the blood (bacteraemia), meningitis and necrotizing fasciitis.

Signs that cellulitis has become severe and spread to other parts of the body

  • Fever
  • Headache
  • Your child looking unwell or feeling very sleepy
  • Vomiting​ (throwing up)
  • Confusion or disorientation
  • Difficulty walking
  • Arm or leg weakness
  • Seizures (shaking of the body that cannot be stopped)
  • Deep pain in the bone or joint
  • Cold, clammy skin
  • Rapidly-spreading redness with severe pain

When to see a doctor

See your child’s doctor when your child first shows symptoms of cellulitis.

Return to your child’s doctor or go the nearest emergency department if your child:

  • cannot take the prescribed antibiotic because they are vomiting often
  • looks unwell or very sleepy
  • has a fever lasting longer than 72 hours after first taking the antibiotic
  • has increased swelling, redness or pain after the first 24 to 48 hours of antibiotic treatment
  • develops red streaks on the skin, spreading out from the initial site of infection
  • has cellulitis around the eyes that does not improve after 24 to 48 hours of antibiotic treatment, causes a change in vision or gives pain when the eye moves.

Key points

  • Cellulitis is a skin infection that causes swelling, redness, pain and heat in the affected area.
  • Cellulitis is treated with antibiotics.
  • Left untreated, cellulitis can spread to other parts of the body and cause severe infections.

Shawna Silver, MD, FRCPC, FAAP, PEng